Published papers

Summary: Following technological advances in endovascular therapy, this approach is preferred over　surgery as the mainstay of treatment for dural arteriovenous fistula (dAVF). However, surgery remains important, and its role should be re-evaluated. In this retrospective study, we investigated the outcomes of surgical treatment for dAVF, focusing on the pitfalls of this approach in 101 patients who underwent surgery for dAVF. We analyzed the characteristics of lesions treated surgically, as well as treatment outcomes including the morbidity, AV shunt occlusion, and recurrence rates. The results included 20 patients who underwent only surgical treatment. The surgical morbidity rate was 5%. All AV shunts were extirpated at radical procedures; however, recurrence occurred in one patient. In conclusion, surgery serves as definitive treatment for specific types of dAVF. Careful decision-making regarding an endovascular vs. an open surgical approach is important, together with preparedness to manage the associated challenges, as observed in this case series.

Dural arteriovenous fistulas (dAVFs) of the lesser sphenoid wing region are rare. We report a case of a dAVF of the lesser sphenoid wing region with leptomeningeal drainage.A 79-year-old man consulted the Department of Neurosurgery for examination of a dAVF of the anterior cranial fossa, which was incidentally revealed on magnetic resonance imaging. Angiography demonstrated a dAVF of the lesser sphenoid wing region; the fistula was supplied by the recurrent meningeal artery (RMA) via the ophthalmic artery and the inferolateral trunk (ILT) from the left internal carotid artery. Multiple feeders were noticed originating from the left external carotid artery, such as the artery of foramen rotundum (AOR), accessory meningeal artery (AMA), and middle meningeal artery (MMA). The fistula drained into the deep middle cerebral vein via the uncal vein and the frontal cortical vein via the superficial middle cerebral vein, which had varices. The patient was scheduled for endovascular treatment, and transarterial embolization (TAE) was performed. The RMA, ILT, and AOR were occluded using platinum coils, while the AMA was occluded using n-butyl-2-cyanoacrylate (NBCA). The fistula was completely embolized via the MMA using NBCA. No adverse events were noticed, and the fistula was successfully obliterated.dAVFs of the lesser sphenoid wing region are rare, and TAE using NBCA is a useful treatment for this condition.

Spinal arteriovenous shunts (SAVS) have several subtypes and accurately understanding its pathophysiology and precise diagnosis is required. Collaboration between interventional vascular specialists and direct surgeons is essential for appropriate treatment. Here, we examined the treatment selection and outcomes of 49 cases with 51 lesions of each shunt type treated at our facility. There were dural lesions in 19 cases, epidural lesions in 12 cases, perimedullary lesions in 10 cases, radicular lesions in seven cases, and three other lesions. Treatment comprised direct surgery in 29 cases (65.9%) and endovascular therapy in 15 cases (34.1%). In all direct surgery cases, the endovascular surgeon shared the treatment strategy with the direct surgeon and provided support for intraoperative shunt identification. In the direct surgery group, 26 lesions were successfully cured (89.7%), while in the endovascular therapy group, 13 lesions showed successful closure or effective embolization (86.7%). The perioperative complications were 4.5%, and no persistent symptoms were observed. In SAVS treatment, the endovascular surgeon performed endovascular intervention, provided accurate diagnoses, including appropriate strategies, such as direct surgery, and offered intraoperative support. This collaborative approach facilitated effective SAVS treatment.

Objective: We report a case of arteriovenous shunt with multilobular venous pouch around the supraorbital fissure, which has not been reported in the literature. Case Presentation: A 51-year-old female with a history of craniotomy with a right frontotemporal approach for the surgical resection of a orbital vascular malformation in childhood. She presented with right eye pain, protrusion, and conjunctival hyperemia of the right eyeball. Angiography revealed multilocular venous cavities near the supraorbital fissure from the sphenoid ridge to the middle skull base, with a relatively localized arteriovenous shunt on the venous wall. The shunt blood flow was supplied by the branches of the external carotid artery and drained into the superior ophthalmic vein. The venous cavity where the arteriovenous shunt was formed was also continuous with the cavernous sinus, but it appeared to be an arteriovenous shunt secondary to venous malformation, as the venous structure was multilocular, rather than a single vein. Selective transvenous embolization was performed, and the arteriovenous shunt disappeared and the eye symptoms disappeared. Conclusion: After surgery for orbital vascular malformations, an arteriovenous shunt may form in the remaining venous wall. Transvenous embolization may be an effective treatment.

＜文献概要＞POINT ▼頭頸部癌の頸動脈浸潤例において,頸動脈合併切除を伴う拡大手術が予後に寄与するかどうかは明らかではないが,切除による長期生存例があることから,症例によって選択肢になりうる。▼頸動脈再建を行う場合には,術前に血管造影検査にて頸動脈遮断テストを行い,一時的な遮断に耐えることができるか評価する。また自家静脈グラフトによる血行再建を行う場合には,採取する血管について評価を行う。▼頸動脈再建手術では,周術期の出血リスクや脳血管障害の発生リスクがある。周術期管理には慎重を期す必要がある。

Objective: Hemangiopericytomas (HPCs) and solitary fibrous tumors (SFTs) have been categorized as the same disease entity, SFT/HPC, since 2016. SFT/HPC is one of the most highly vascularized brain tumors, distinct from meningioma. The angioarchitecture also differs between these tumors. Understanding these differences can help interventionalists perform presurgical embolization more safely and effectively.Methods: Vascular structures were analyzed in eight patients with central nervous system (CNS) SFT/HPCs, all of whom received presurgical embolization. The type of embolic materials used and the complication rates were compared between the CNS SFT/HPC cases and 39 meningioma cases treated within the same period. Characteristic angiographic features of SFT/HPC were identified, and we present their interpretation and utilization to inform embolization strategies.Results: Four angiographic features of SFT/HPCs were identified. 1) Persistence of tumor stain and 2) feeders from branches of the internal carotid artery or vertebral artery were observed in all cases, while 3) connecting feeders (highly dilated vessels that originate from branches of other feeder vessels and run along the surface of one tumor compartment to feed another compartment) were observed in five out of eight cases. 4) Finally, an intratumoral arteriovenous shunt was identified in one case. The frequency of liquid embolic material use was significantly higher in SFT/HPC cases than in meningioma cases. No complications were observed in SFT/HPC cases, and all tumors were effectively removed.Conclusion: The most appropriate presurgical embolization strategies differ between SFT/HPCs and meningiomas depending on the tumor angioarchitecture. A thorough understanding of the vascular anatomy is necessary for safe and effective embolization of SFT/HPCs.

Background: Some reports suggest the efficacy of mechanical thrombectomy (MT) for acute vertebrobasilar artery (VBA) occlusion. The major causes of VBA occlusion include cardioembolism (CE) and large-artery atherosclerosis (LAA). However, the clinical characteristics of each cause remain unclear, and they might be important for decision making related to the indications and strategy of MT. Objective: This study aimed to compare functional outcomes and factors affecting outcomes between patients with CE and LAA with acute VBA occlusion. Methods: This was a retrospective and prospective observational study using data from TREAT (Tokyo-Tama-Registry of Acute Endovascular Thrombectomy), a multicenter registry of MT for acute large-vessel occlusion in the Tokyo metropolitan area. Patients with VBA occlusion classified into CE and LAA groups were analyzed. The primary outcome was a modified Rankin Scale score of 0–2 at 90 days. Results: Seventy-nine patients (57 with CE and 22 with LAA) were eligible from January 2015 to March 2020. Despite significantly shorter puncture-to-recanalization and onset-or-last-well-known-to-recanalization times in the CE group, the primary outcome was not significantly different between the 2 groups (CE, 31.6% vs. LAA, 45.5%; P = 0.248). In the subgroup analysis, patients with CE had worse clinical outcomes in the onset-or-last-well-known-to-door time ≥180 minutes, onset-or-last-well-known-to-door time ≥300 minutes, and low posterior circulation Alberta Stroke Program Early CT Score (≤7) subgroups. Conclusions: Functional outcomes of VBA occlusion were not significantly different between CE and LAA. Based on the subgroup analysis, patients with CE might have poorer collateral status than do patients with LAA, and earlier recanalization might therefore be desired.

Objective: Cone-beam computed tomography (CBCT) images for skull base tumors provide detailed vascular information and localization in regard to surrounding bony structures. We report use of the CBCT fusion technique for skull base meningiomas. Methods: Six patients with petroclival or petrotentorial meningiomas supplied by multiple arterial systems were preoperatively evaluated using CBCT fusion imaging. Fusion images were reconstructed from three-dimensional rotational angiography with contrast agent injections from the internal carotid artery (ICA) and external carotid artery in 4 cases, vertebral artery and external carotid artery in 1 case, and ICA and vertebral artery in 1 case. Results: The feeding pedicles and tumor stains from 2 arterial systems were differentiated by separate colors. The courses and territories of the ICA dural feeders or ICA/vertebral artery pial feeders were easily distinguished from the external carotid artery dural feeders. Anastomoses between thin feeders from different arterial systems could be detected. Mixed stain (stain with both colors) was observed in some tumor compartments, suggesting dual supply from 2 arterial systems and the presence of peritumoral anastomoses. All patients underwent preoperative embolization without complications. Conclusions: CBCT fusion images clearly visualized the feeders from each arterial system, the vascular compartments within the tumor, and possible peritumoral anastomoses. This technique provides a substantial contribution to both preoperative embolization and surgical resection of skull base meningiomas.

Introduction: Although the ascending pharyngeal artery (APhA) is known as a main feeder of carotid body tumors (CBTs), its detailed architecture and embryological consideration have not been described. The objective of this study was to describe the architecture of a descending feeder of the APhA and to consider its origin embryologically through a review of our CBT embolizations. Methods: We retrospectively analyzed data from patients with CBTs who underwent transarterial embolization or angiographic examination–only between July 2010 and February 2017. The arterial supply of the tumors, the number of feeder pedicles, the mean tumor size, embolization materials, complication of embolization, and extent of tumor removal were assessed. The embryological origin of feeding artery was considered based on the literature. Results: Eighteen patients with 20 CBTs underwent preoperative embolization or angiographic examination. The number of feeder pedicles was significantly related to the size of the CBT (P = 0.0002). The main feeding artery was the descending branch of APhA, which was hypertrophied and tortuous (18/20, 90%). Embryologically, this artery originated from the musculospinal branch and is termed the “descending musculospinal branch”. Conclusion: The main feeder of the CBTs was the “descending musculospinal branch” of the APhA and needs special consideration such as dangerous anastomosis for embolization.

Objective: Brain tumors often become clinically evident during pregnancy; however, the mechanism has not been well elucidated. Purpose of this study is to investigate the influence of molecular genetic factors on the progression of brain tumors during pregnancy or the postpartum period. Methods: Twelve cases of brain tumors that presented during pregnancy or postpartum period were included: five gliomas, three meningiomas, two vestibular schwannomas, and two chordomas. Tumor samples were investigated by metaphase comparative genomic hybridization and immunohistochemistry, for chromosomal copy number aberration (CNA) and receptor expression of sex hormones and growth factors. Results: The results were correlated with the timing of tumor presentation in relation to the stage of pregnancy. EGFR, VEGFR-1/2, AR, and c-Myc were expressed in gliomas, PgR, ER, HER-2, VEGFR-1, EGF and VEGFR2 in meningiomas, VEGFR-1 in vestibular schwannomas, and EGFR, VEGFR-1/2, and c-Myc in chordomas. The CNAs of the tumors varied. Four of the five gliomas presented in the 2nd trimester, all three meningiomas in the 3rd trimester or postpartum period, and both of the two schwannomas in the late 2nd trimester. Expression of VEGFR-1/2 and EGFR was observed regardless of the timing of tumor presentation, whereas female hormone receptors and HER-2 were exclusively found in meningiomas. Interestingly, one anaplastic astrocytoma (IDH mut, non-codeleted) that progressed from precedent grade 2 tumor harbored amplification of the MYC locus. Conclusion: Progression of brain tumors during pregnancy is associated with various growth factors as well as sex hormones. The timing of presentation is likely dependent on molecular receptors specific to each tumor type.

Cerebral hyperperfusion syndrome is a rare but severe complication of carotid artery stenting or carotid endarterectomy. Staged angioplasty is reportedly an effective strategy to avoid cerebral hyperperfusion syndrome. We encountered a case of internal carotid artery stenosis with a rare clinical presentation of limb shaking that was successfully improved by staged angioplasty. To our knowledge, there are no reported cases of limb shaking treated with staged angioplasty. A 76-year-old woman presented with continuous chorea in her left lower limb and shoulder. Medical examination revealed a tiny cerebral infarction in the right corona radiata and severe right internal carotid artery stenosis. Angiography showed near occlusion of the right internal carotid artery. Staged angioplasty was performed to avoid the risk of cerebral hyperperfusion syndrome. The first angioplasty resulted in an expanded diameter of 2.5 mm and was followed by definitive carotid artery stenting using a closed-cell stent 3.5 weeks later. Limb shaking improved in a stepwise manner along with an improvement in internal carotid artery stenosis and distal flow state with no signs of cerebral hyperperfusion syndrome. Patients with internal carotid artery stenosis or occlusion presenting with limb shaking have been suggested to have impaired cerebrovascular reactivity, which is also thought to be a risk factor for cerebral hyperperfusion syndrome. The stepwise improvement in limb shaking observed in this case supports the idea that the pathophysiology of limb shaking is related to cerebral haemodynamic impairment. Measures to prevent cerebral hyperperfusion syndrome, including staged angioplasty, should be actively considered in patients with limb shaking because the symptoms themselves suggest severe hypoperfusion.

Introduction: Although spinal arteriovenous fistula (AVF) has been reported widely, AVF at the cauda equina is quite rare. We described a case of AVF at the cauda equina that was fed by the distal radicular artery (DRA). Case presentation: A 50-year-old woman presented with sudden weakness of the lower extremities. Magnetic resonance imaging (MRI) revealed a lesion with a highly intense signal at the conus medullaris, which was surrounded by several low-intensity signals (flow voids). Digital subtraction angiography revealed AVF at the cauda equina and that it was fed by the DRA, which was directly fed by the L3 segmental artery. We performed surgical resection of the AVF while monitoring motor-evoked potentials. The patient’s postoperative course was uneventful, and her neurological symptoms gradually resolved. MRI 2 years after surgery showed the disappearance of both intramedullary edema and the flow voids. Discussion: For the AVF, located at the cauda equina and fed by the DRA in this case, surgical resection or endovascular embolization could have been selected. We performed open surgery to achieve complete obliteration of the AVF, which led to postoperative functional recovery without any adverse events. However, only a limited number of AVFs at the level of the cauda equina have been reported, and treatment standards have not been established. Further studies of AVFs at the cauda equina are necessary to clarify the epidemiological characteristics and clinical outcomes with an appropriate sample size.

Background: The coexistence of vascular malformations in the conus medullaris and cauda equina has been rarely reported, and the complex angioarchitecture in multiple arteriovenous lesions remains poorly understood. Case description: A 17-year-old woman presented with a sudden-onset, stepwise worsening of weakness and pain in the bilateral legs. Angiography revealed conus medullaris arteriovenous malformation and cauda equina arteriovenous fistulas. One of the drainers was shared between the coexisting lesions and harboured a varix. Targeted embolisation of a fistulous point in the conus lesion was performed with precaution to prevent occluding the common drainage route, which led to symptom improvement with angiographical diminishment of the varix. Conclusions: Recognising that communications between drainers can be observed in multiple spinal arteriovenous lesions is important in facilitating a safe embolisation. Cautious assessment of angiogram with fusion images of cone-beam computed tomography and volumetric T2 magnetic resonance imaging can help in establishing the diagnosis and treatment strategy.

Objective: Pseudoaneurysms of the internal carotid artery (ICA) and sphenopalatine artery (SPA) are recognized as sources of arterial epistaxis following head and face trauma. However, epistaxis involving pseudoaneurysm of the anterior ethmoidal artery (AEA) is extremely rare.Case Presentation: A 25-year-old man experienced massive epistaxis due to a ruptured traumatic pseudoaneurysm of the AEA. The patient had suffered head and face trauma in a car accident. CT showed fractures of the frontal, ethmoidal, and maxillary bones, and he was managed conservatively. Nine days after the injury, he had sudden, massive epistaxis. Angiography showed a right AEA aneurysm, which was treated successfully with transarterial embolization using n-butyl-2-cyanoacrylate (NBCA).Conclusion: Although pseudoaneurysm of the AEA is a rare cause of epistaxis, it is important to consider this diagnosis, in addition to pseudoaneurysm of the SPA and ICA, when a patient has massive arterial epistaxis following a traumatic skull base fracture, especially if the fracture is adjacent to the ethmoid sinus. Transarterial embolization using glue is a feasible therapeutic option for this condition.

Background: Vasa vasorum (VVs) is a Latin word representing vessels of vessels. VVs are usually found on the adventitia of the parent vessel and infrequently reach the media and intima, depending on the size and type of the parent vessels and physiological and pathological conditions. The VVs include arteries, capillaries, veins, and lymphatic vessels, involving the oxygenation and nourishment of the vessel’s wall to sustain its healthy state. Accumulated studies have revealed that VVs are involved in various intracranial lesions, including atherosclerotic diseases, aneurysms, and shunt diseases. The current review aims to review and integrate past and recent findings and knowledge on VVs and to facilitate our understanding of VVs and intracranial pathology involving VVs. Methods: A literature review was carried out with a focus on the role of VVs by searching the Pubmed database. Results: We identified 71 articles that discuss the role of VVs. We discussed the anatomical structure, physiological significance, and pathological significance of the VV. Conclusion: VV is not only involved in the nutrition and metabolism of the vascular wall but is also deeply involved in the pathogenesis of inflammation, ischemia, and thrombosis of the vascular wall. In addition, in the central nervous system, intracranial vascular wall nutrient particularities and VVs are closely related to the pathogenesis of cerebral aneurysms, subarachnoid hemorrhage, arteriovenous shunt disease, atherosclerotic lesions, and other conditions.

OBJECTIVES: Spinal dural arteriovenous fistula (sDAVF) is a rare and often underdiagnosed spinal disease. Early diagnosis is required because the deficits are reversible and delays in treatment cause permanent morbidity. Although the abnormal vascular flow void is a critical radiographic feature of sDAVF, they are not always present. A characteristic enhancement pattern of sDAVF has been recently reported as the "missing-piece" sign which can lead to the early and correct diagnosis. METHODS: We presented imaging findings, treatment decisions, and the outcome of a rare case of sDAVF, in which the "missing-piece" sign appeared atypical. RESULTS: A 60-year-old woman developed numbness and weakness in her extremities. Spinal MRI revealed longitudinal hyperintensity in the T2-weighted image, extending from the thoracic level to medulla oblongata. At first, myelopathy with inflammation or tumor was suspected because of the lack of flow voids and vascular abnormalities in CT-angiography and MR-DSA. However, we administered intravenous methylprednisolone and her symptom got worse with the appearance of the "missing-piece" sign. Then, we successfully diagnosed sDAVF by angiography. The "missing-piece" sign was considered to derive from inconsistency of the intrinsic venous system of spinal cord, with the abrupt segments without enhancement. The same etiology was considered in our case. CONCLUSIONS: Detecting the "missing-piece" sign can lead to the correct diagnosis of sDAVF, even if the sign appeared atypical.

Patients with neurofibromatosis type 1 not only have characteristic skin findings but are also known to have vascular disorders due to vascular vulnerability. A 44-year-old man with previously undiagnosed neurofibromatosis type 1 was brought to the emergency room due to a sudden subcutaneous hematoma with no history of trauma. Angiography revealed extravasation from the parietal branch of the right superficial temporal artery, which was embolized with n-butyl-2-cyanoacrylate. However, the next day, the patient exhibited an increased subcutaneous hematoma, and new extravascular leakage was detected at the frontal branch of the superficial temporal artery, which was also embolized with n-butyl-2-cyanoacrylate. The patient had physical findings characteristic of neurofibromatosis type 1, such as café-au-lait spots, and was subsequently diagnosed with neurofibromatosis type 1. No obvious neurofibroma or any other subcutaneous lesion associated with neurofibromatosis type 1 was identified in the affected area. Massive idiopathic arterial bleeding in the scalp, although infrequent, can be fatal. Neurofibromatosis type 1 should be considered when a subcutaneous scalp hematoma is observed without a history of trauma, even if the facial skin structure appears normal. Neurofibromatosis type 1 is also known to have multiple sources of hemorrhage. Thus, it is important to repeatedly evaluate vascular structures via cerebral angiography, contrast-enhanced computed tomography, and magnetic resonance imaging, if necessary.